New process for introducing sulphocyanic groups in organic compounds



Patented Jan. 27, 1931 UNITED STATES PATENT, orrlcr.

me PAUL KAUIIANN, OF JENA, GERMANY, ASSIGNOB TO 1'. FARBENDTDUSTBIE AKTENGESELIBCHAIT, OF rmxroa'r-ou-rnn-mm, A OOBPOM'IION 01' em- MANY mew rnoonss roa mrnonuomc sunrirocvmrc eaours m ommc oolrrounns Io Drawing. Application filed Lugult 21, 1926, Seriallio. 180,770, and in Germany August 37, 1925.

The present invention relates to a new process for introducin sulphocyanic groups into organic compoun s and to new products obtainable thereby.

5 My new process consists in causing an inorganic sulphocyanic salt in solution together with a halogen to react on an organic compound.

. The reaction can be effected in an aqueous 0 or an acid medium, the new process being therefore of wide application and allowing the production of various organic sulphocyanic compounds of different classes on a technical scale.

It is possible to introduce one or more sulphocyanic groups into aliphatic as well as aromatic; compounds according to the capability of the organic compound in question of forming derivatives.

When using aromatic compounds as starting materials, I prefer to use such aromatic compounds as are substituted by a substituent of the group including amino, substituted amino, hydroxyl, and the desmotropic kcto group. It is well known in the art that these compounds possess a labile hydrogen atom and are in consequence thereof highly reactive.

The following scheme of formulas may illustrate the probable course of reaction, however I do not wish to bind myself to this scheme in any way.

The introduction of a sulphocyanic group into aniline may be taken as a simple example:

(1) 2NaB ON+Bn=-2NaBr+(S ON): 2 o HNHH-(S ON) -0 H +nsoN i SON mscN wherein R means an organic residue of the aliphatic or aromatic series, which may contain further substituents, n means the number 1 or 2. The are valuable from a therapeutical point 0 view and as intermediates for able for producing dyestuffs of, different classes.

In order to obtain these products of conversion it is not necessary to isolate the organic sulphocyanic compounds. For instance one may saponify immediately a formed 'sulphocyanic compound by addmg an alkaline lye to the reaction mass in order to form the corresponding disulfide, whereas by further adding a reducing agent mercaptans are obtained.

In order to further illustrate my invention the following examples are given; I wish it however understood that I am not limited to the particular examples given nor to the specific conditions mentioned; The parts are b weight and all temperatures in centigra es.

Example 1' is soluble in water and the usual organic solvents and melts in a pure state at 90 (see Archiv der Pharmazie (2) vol. 85, page 1).

(b) 10 parts of sodium sulphocyanide are dissolved in parts of hydrochloric acid of 15% strength. Then a strong current of ethylene is allowed to passthrough the well coo ed solution and 6 parts of bromine, dissolved in a suitable amount of hydrochloric acid, are dropped in slowly. The formed ethylene-disulphocyanideis isolated, as described above.

In the same manner sulphocyanic groups may be introduced into acetylene.

Example 2 Hz-BGN melting at 101 (see Liebigs Annalen vol. 216, page 324).

Example 3 90 parts of sodium sulphocyanide are dissolved in 500 parts of acetic acid and2,8 parts of anethol are added. Then 32 parts of bromine are allowed to flow into slowly while well cooling. After short time the same volume of water is added and after some time the product of reaction separates. The formed 1-p-methoxy-phenyl-1.2-disulphocyanogenopropan of the formula:

04 ON (L H H-SCN melts, when recrystallized from carbondisulfide and ether, at 87. (see Ber. deutsch. pharm. Ges. vol. 33, page 139).

Example 4 (a) 5,6 parts of aniline are added to 100 parts of a saturated aqueous solution of ammonium sulphocyanide. Then 9,6 parts of bromine are allowed to flow into the solution while well stirring and cooling. After cooling the solution with a freezing mixture for some time the formed para-sulphocyanogeno-aniline of the formula HzNO-SCN separates in form of the sulphocyanic salt. It is decomposed by washing it with a sodium carbonate solution. The para-sulphocyanogen-aniline thus obtained melts, when recrystallized from hot water, at 57-58 (see Liebigs Annalenvol. 419, page 271).

(b) A solution of 4,6 parts of aniline in 120 parts of acetic acid is mixed with a solution of 250 parts of sodium sulphocyanide in 1300 parts of acetic acid. Then 96 parts of bromine are dro ped into the mixture while well cooling and stirrin After some time the formed para-sulp ocyanogeno-aniline separates almost colorless from the well cooled solution.

The filtrate is diluted with about the triple volume of water and neutralized with solid sodium carbonate. The separated crystals melt, when recrystallized from water, at

198. They are probably the hitherto unknown 2.4-disulphocyanogeno-aniline of the soN Example 5 2 parts of di henylamine are dissolved in parts of di ute sulfuric acid (15 p. c.) and then 20 parts of sodium sulphocyanide formula are added,dissolved in the same solvent; A

solution of the calculated quantity of bromine in dilute sulfuric acid is introduced while well cooling, and the solution is cooled by a. freezing mixture. After some time the formed para -disulphocyanogeno diphenylamine of the formula separates in form of yellow flakes. When recrystallized from dilute alcohol it melts at 1?0) (see Liebigs Annalen, vol. 419, page 2 6 Example 6 14 parts of salicylic acid and 40 parts of sodium sulphocyanide are dissolved in 300 parts of formic acid. while warming. Then 30 parts of bromine, dissolved in the same solvent, are added. Eventually separating products of olymerization are removed by filtration. en the solution is poured into water and extracted with organic solvents. After evaporating them the residual 5- sulphocyanogenosalicylic acid of the formula is obtained, melting in a ure state at 165 (see Ber. deutsch. chem. es., vol. 56, page 2519 and vol. 58, page 1556).

. Exwmple 7 42 parts of a-naphthol are dissolved in 200 parts or acetic acid and parts of sodium sulphocyanide are dissolved in 650 parts of acetic acid (96%) and to the mixture of both solutions48 parts of bromine, dissolved in 150 parts of acetic acid, are added in the .described manner. The clear solution is then diluted with about the triple quantity of water and after some time a pulp of crystals separates. They are filtered and dissolved in ether, the ether is evaporated and the residue is recrystallized from carbon disulfide. In this manner 4-sulphoeyanogeno-1-naphthol of the formula:

- CN- melting at 113, is obtained (see Ber. d. deutsch. chem. Ges. vol. 58, page 1555).

E wainple 8 10 parts of a-naphthol are dissolved in 120 parts of acetic acid and 80 parts of potassium sulphocyanide are dissolved in 350 parts of acetic acid and to the mixture of both solutions 19 parts-of bromine, dissolved in 120 parts of acetic acid, are added in the described manner. The shortly separating pulp of crystals is filtered and washed. The residue is dissolved in alcohol and the alcoholic solution is precipitated by addition of water. In this manner as a new compound 2.4-disulphocyanogeno-l-naphthol of the probable formula SCN is obtained in form of yellowish needles,

melting at 118-119 under decomposition.

In the same manner one or two sulphocyanic groups may be introduced in ,B-naphthol.

E wample' .9

(a) 20 parts of a-naphthylamine are suspended in 400 parts of a saturated aqueous solution of ammonium sulphocyanide, then 30 parts of bromine are added while well cooling. The separated reddish product of reaction is filtered, washed with a sodium carbonate solution and recrystallized from alcohol. As a new compound 2.4-disulphocyanogeno-l-naphthylamine of the probable formula soN

is obtained, it is easily soluble in the usual organic solvents, melting at 204.

(6) 42 parts of a-naphthylamine are dissolved in 200 parts of acetic acid and 170 parts of sodium sulphocyanide are dissolved in 880 parts of acetic acid and to the mixture of both solutions 96 parts of bromine, dissolved in 250 parts of acetic acid, are added. The formed white precipitate is filtered and recrystallized from alcohol. It isv identical with the aforesaid 2.4-disulphocyanogeno-1- naphthylamine.

Emample 10 A solution of 71 parts of fi-naphthylamine in 450 parts of acetic acid is mixed with a solution of 160 parts of sodium sulphocyanide in 1200 parts of acetic acid. To the mixture, in which partly the sulphocyanic salt of fl-naphthylamine separates, 80 parts of bromine, dissolved in 350 parts of acetic acid, are

added while cooling. During the addition of bromine the precipitate disappears and the solution becomes clear. When the whole quantity of bromine is dropped into the solution, a new precipitate separates, which is filtered and washed with' sodium carbonate solution. When recrystallized from alcohol, benzene or carbon tetrachloride, a new body is obtained, easily soluble in the usual solvents, and melting at about 261 with a total decomposition after having frit at 150-1549 It is probably the hitherto unknown l-sulphocyanogeno-2-naphthylamine of the formula SON It is advisable to carry out the reaction at lower temperatures by cooling the mass, or, when working at ordinary temperatures, to isolate immediately the l-sulphocyanogeno- .Z-naphthylamine formed, as otherwise when allowing the reaction mass to stand or on warming it, the isomeric thiazole compound is obtained.

E mample 11 19 parts of antipyrin and 20 parts of sodiis obtained in a pure state without any further purification, showing immediately the melting oint of 256; given in literature for this pr uct. I claim:

1. A process which comprises causing an inorgamc sulphocyanic salt and a halogen to act in an or anic acid solution on an organic compoun A 2. A process which comprises causing an inorganic sulphocyanic salt and a halogen to act in an acetic acid solution on an organic compound.

3. A process which com rlses causin an inorganic sulphocyanic sa t in a disso ved form and a halogen to act on an aromatic compound of the naphthalene series.

4. A process which comprises causin an inorganic sulphocyanic salt in a disso ved form and a halogen to act on a naphthylamine body.

5 Asnew products organic sulphocyanic compounds of the formula:

in which formula the'Xs mean hydrogen atoms, of which one or more may be replaced by a monovalent substituent, n means the number 1 or 2, which compounds are when dry almost colorless powders, soluble in the usual organic solvents.

6. As a new product 1-su1phocyanogeno-2- naphthylamine of the formula:

SUN

melting at about 261, soluble in the usual or anic solvents.

A process which comprises causing an inorganic sulphocyanic salt in a dissolved form and a halogen to act on an aromatic compound which is substituted by a substituent having a labilizing effect of the group including amino, substituted amino, by,- droxi and the desmotropic keto group and whic may be further substituted.

8. A process which comprises causing an inorganic sulphocyanic salt in a dissolved form and a halogen to act on a com ound of the naphthalene series which is su stituted by a substituent having a labilizing effect of the group includin amino, substituted amino, hydroxyl, an the desmotropic keto group and which may be further substituted.

9. A process which comprises causing an inorganic sulphocyanic salt and a halogen to 'actm an organic acid solution on an aromatic compound. I

In testimony whereof, I afiix my signature. HANS PAUL KAUFMANN. 

